Groundwater vulnerability risk assessment in south Darb El Arbaein, south Western Desert

Abstract

Abstract Groundwater resources in the south Darb El Arbaein are currently threatened by agricultural impact and rock water interaction associated with over exploitation. Planning of Nubian sandstone aquifer is required, especially in this new invest area. It is implemented by GIS to establish vulnerability areas and to evaluate protocol plans for hydrogeological parameters and soil. The TDS concentration ranged from 750 to 1350 ppm, confirms the impact of non-point source (agricultural activity). It is because recharging Nile water has TDS concentration of 100–300 ppm. Aquifer vulnerability delineation areas by lithogenic and anthropogenic sources have been recently highlighted for water resources systems planning and management. The correlation among hydrogeological, geological, and hydrogeochemical characteristics was discussed and achieved. Ten stratified beds were matched by GIS with specified average weights to them according to their relative importance for groundwater vulnerability. The chosen layers are TDS, aquitard thickness, water depth, hydraulic conductivity, transmissivity, slope, total hardness (TH), sodium adsorption ratio (SAR), discharge rate (Q), and screen length. The groundwater impact distribution reflect five categories ranged from no to excellent aquifer potential levels. Class I (very low vulnerability) was in the northern part and contains 11.1% (16.02 km2) of the area. While very high vulnerability (class V) was in southeast, east, it represents 10.4% (14.96 km2). The preferred invested area was northeast rather than other areas; otherwise, the groundwater degradation enhanced. The vegetation/ or barren lands were established by band 4/band 3, band 3/band 4 ratios and composite RGB 7, 4, and 1 satellite images.

Keywords

• Hydrogeology
• Groundwater vulnerability
• GIS-RS
• South Darb El Arbaein. south Western Desert